USB battery pack keeps powering pi when I turn it off

[suse_m]

I just received the USB BATTERY PACK FOR RASPBERRY PI - 10000MAH - 2 X 5V @ 2A yesterday. I hooked it up to a pi and a 10inch screen (https://www.adafruit.com/products/1287). working nicely but when I turn off the battery it continues to power the pi and the screen, which obviously draws all the power out of the battery pack till it's completely empty.
anyone experienced anything similar? What would be an easy solution? (as I'm planning to put a casing around the whole thing unplugging the usbs isn't an option)

[adafruit_support_rick]

Are you sure you're turning the battery off? Perhaps you're only turning off the blue LEDs? Try pressing the button again.

[johnw17]

This sounds like the same problem I just posted about with a 4400 mAH battery supply. When I press the button again, the leds come back on. Is there some trick involving pressing the button for a few seconds to turn the output off (but not long enough to turn the 'flashlight' led on)? Or perhaps pressing it twice in rapid succession? Or....?

[adafruit_support_rick]

I don't have one of the 10000mAh batteries, but I do have the 4400. It looks like you can't turn it off. Short clicks toggle the blue LEDs. Long clicks toggle the flashlight.

[johnw17]

suse_m - you might consider using an 'intelligent shutdown switch', like the one I have from Mausberrycircuits.com. It seems to be working OK now, although it didn't at first - I had to change one of the default GPIO pins to get it to work. I am a little concerned that it seems somewhat in a hurry to shut off power after the shutdown command is issued; in my experience, the last thing that happens after a shutdown is the 'Act' led blinking ten times; the Mausberry switch only allows time for six blinks before pulling the plug. There is also an apparently similar 'ATXraspi' switch from lowpowerlab.com which I haven't tried.

[suse_m]

so the answer is that I have to power down manually using some extra component? Would a normal button work or does it need to be this "intelligent shutdown button" or would a normal toggle switch do the job?
as far as I see the switches recommended by @johnw17 just shut down the power towards the Pi. So I assume the battery just goes into some kind of sleep-mode when there is no power consumed by the pi and, in my case, the screen?

[adafruit_support_mike]

The power brick has an internal shutdown circuit that should automatically cut power when the load falls below a certain limit for a certain amount of time. The exact values aren't documented.

I just measured a RasPi's current load from boot to full shutdown, and the shutdown level was a steady 112mA. That's probably enough to keep the power brick running.

If you're doing a full shutdown, you'll need to interrupt power to make the RasPi boot again anyway. A mechanical toggle switch would work, or you can use something like this:
https://www.adafruit.com/product/1400

[suse_m]

yeah. I just soldered the thing together with the mechanical toggle and the battery does turn off now. however, when trying to wake it up again I have to switch the toggle (of course) but also press the button on the battery, which is kinda annoying. Would there be any solution for that?

[suse_m]

oh and another (not) great thing I discovered: I'm now powering both devices (pi and screen) from the 2.1A output USB. It works nicely when I just use the battery. However I want an option that lets me run it via a power-court. Now what I do is I connect the micro-USB in order to charge the battery (with a 5V 2A power supply) and at the same time I run the pi and the screen. Pi seems to run ok, but screen starts flickering. It's weird because the screen uses ca. 980mA and the pi supposedly uses something like 1A, so it should totally be enough to power both, right? Or is there any mistake in my thinking?

[adafruit_support_rick]

Now what I do is I connect the micro-USB in order to charge the battery (with a 5V 2A power supply) and at the same time I run the pi and the screen. Pi seems to run ok, but screen starts flickering. It's weird because the screen uses ca. 980mA and the pi supposedly uses something like 1A, so it should totally be enough to power both, right? Or is there any mistake in my thinking?

There's a ~80% efficiency between the charging and power supply ends, so if you're powering it at 2A and drawing 2A at the same time the battery will eventually discharge completely.

[suse_m]

yeah, but my battery is full but the screen still flickers. So if I buy a power supply of 3A that should be fine? the product description says "The charging circuit will draw 1A from a 5V supply", so then if I need to provide 2 amps still at the output I should have 3A in the input, right?

[adafruit_support_rick]

No. If it only draws 1A, then that's all it will draw.

So, your screen flickers with a full battery when it's connected to charge, but it doesn't flicker otherwise?

[suse_m]

yes exactly, that's the case.
so if the Amps of the power supply aren't the issue, what else might be the issue then? it used to work when I still powered screen and pi separately via the 2 usb plugs, but now since now I need have the toggle-switch I'd need 2 switches and it's not very user-friendly idea...

[adafruit2]

Yah so it sounds like you are trying to use the battery pack as a 'UPS' - which it is not good at :)

The charging circuit will draw 1A from a 5V supply (plug a microUSB connector into the pack and then to a computer or wall adapter). You can charge and power something at the same time but the output switches to the USB input when charging so the output voltage may fluctuate. Its not good as a 'UPS' power supply for an embedded linux board

if you want a 'UPS' able power supply, we have
https://www.adafruit.com/product/1944
which does not do the switch around when charging, it always keeps a steady output. it also has pads for on/off but it's not as high current and battery is not included.

[adafruit2]

for the on/off switch, you may want to use somethign like this:
https://www.adafruit.com/product/1620